3 * An interval list used to map matrix elements into integers in the range 0 to
4 * 254 representing shades of gray on a PostScript printer. The list can be given
5 * using the -i option or can be set in the optional header that can preceed each
6 * matrix. The list should be a comma or space separated list that looks like,
10 * where each num is a floating point number. The list must be given in increasing
11 * numerical order. The n numbers in the list partion the real line into 2n+1
14 * region1 element < num1
15 * region2 element = num1
16 * region3 element < num2
17 * region4 element = num3
21 * region2n element = numn
22 * region2n+1 element > numn
24 * Every number in a given region is mapped into an integer in the range 0 to 254
25 * and that number, when displayed on a PostScript printer using the image operator,
26 * prints as a square filled with a gray scale that reflects the integer that was
27 * chosen. 0 maps to black and 255 white (that's why 255 is normally omitted).
29 * The shades of gray chosen by the program are normally generated automatically,
30 * but can be reassigned using the -g option or by including a grayscale line in
31 * the optional header. The grayscale list is comma or space separated list of
32 * integers between 0 and 255 that's used to map individual regions into arbitray
33 * shade of gray, thus overriding the default choice made in the program. The list
36 * color1,color2, ... ,color2n+1
38 * where color1 applies to region1 and color2n+1 applies to region2n+1. If less
39 * than 2n+1 numbers are given the default assignments will be used for the missing
40 * regions. Each color must be an integer in the range 0 to 255.
42 * The default interval list is given below. The default grayscale maps 254 (almost
43 * white) into the first region and 0 (black) into the last.
47 #define DFLTILIST "-1,0,1"
51 * The active interval list is built from an interval string and stored in an array
52 * whose elements are of type Ilist.
57 double val; /* only valid in kind is ENDPOINT */
58 int color; /* gray scale color */
59 long count; /* statistics for each region */
64 * Non-integer function declarations.